Obviously not healthy at all or sustainable in the long term, but will work in terms of results, calories in and calories out.
Not healthy?
Why, if you are concerned about the lack of vitamins and minerals then take a multi-vit/min.
I always find it funny when "hardcore" bodybuilders eat chicken and rice 6 times a day and bang on about health.
a slice of pizza contains more vitamins and minerals than chicken and rice and they could replace two chicken meals for pizza as long as the cals were the same and lose the same amount of fat and be "healthier" in the process.